Simplify the following expression: $z = \dfrac{10}{8k - 2} \div \dfrac{2}{7k}$
Solution: Dividing by an expression is the same as multiplying by its inverse. $z = \dfrac{10}{8k - 2} \times \dfrac{7k}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $z = \dfrac{ 10 \times 7k } { (8k - 2) \times 2}$ $z = \dfrac{70k}{16k - 4}$ Simplify: $z = \dfrac{35k}{8k - 2}$